3D printed drone for low-cost one-way missions

By Edd Gent

Published Friday, March 28, 2014

A 3D printed drone could be made cheap enough to be disposable making it suitable for one-way missions.

Engineers at the Advanced Manufacturing Research Centre (AMRC) at the University of Sheffield have successfully printed a 1.5m-wide prototype unmanned aerial vehicle (UAV) for a research project looking at 3D printing of complex designs.

The engineers said the polymer-based vehicle could form the basis of cheap and potentially disposable UAVs that could be built and deployed in remote situations potentially within as little as 24 hours.

The drone has already completed a test flight as a glider and researchers are developing an electric ducted fan propulsion system that will be incorporated into the airframe’s central spine. They are currently exploring adding a GPS guidance system and whether an operator using first person-view goggles and cameras on the UAV could pilot the vehicle.

Dr Garth Nicholson who led the project said: “Following successful flight testing, we are working to incorporate blended winglets and twin ducted fan propulsion. We are also investigating full on-board data logging of flight parameters, autonomous operation by GPS, and control by surface morphing technology. Concepts for novel ducted fan designs are also being investigated”.

The Sheffield UAV is comprised of nine parts that can be snapped together and it weighs less than 2kg. It was made using a Stratasys Fortus 900mc Fused Deposition Modelling (FDM) machine from ABS thermoplastic, but the engineers are currently evaluating the potential of nylon as a printing material that would make the UAV 60 per cent stronger with no increase in weight.

Earlier versions of the drone required significant amounts of support material around component parts to prevent the airframe structures from deforming during the build process, which added to costs and significantly increased build time, in some cases by an order of magnitude.

The way round this was a more efficient self-supporting design, but this constrained the maximum angle of the machines vertical orientation, or layer height, placing onerous geometrical constraints on the designer.

John Mann, the engineer responsible for detail design and CAD modelling of the aircraft, said: “The whole airframe was designed specifically for additive manufacture. The optimum configuration for the diverse requirements of aerodynamic performance and FDM manufacture appeared to be the blended-wing-body.

“This type of design has a number of advantages: Primarily for this project, it lends itself to FDM technology due to the smooth leading and trailing edges over each half-span.”

This configuration allowed all geometry to remain below the critical angles beyond which support material would be required as well having aerodynamic advantages over conventional fuselage and wing designs.